Abstract
The mechanism of the dehydration and condensation reaction taking place during calcination of Co1/2Ca1/2(H2PO4)2.2H2O has been followed by means of thermal analyses at non-isothermal (dynamic) and at quasi-isothermal-isobaric conditions. Isothermal calcination of starting binary dihydrogenphosphate was carried out in electric oven at various temperatures. The reaction intermediates and products obtained were analyzed by instrumental analytical methods and extraction experiments with solutions of inorganic compounds and with organic reagents. Effect of water vapour pressure has been followed on course, rate and yield of the condensation reactions and of the formation of main considered product-binary cyclo-tetraphosphate (tetrametaphosphate)c-CoCaP4O12.
Zusammenfassung
Mittels Thermoanalyse bei nichtisothermen (dynamischen) und bei quasi-isotherman-isobaren Bedingungen wurde der Mechanismus der Dehydratations- und der Kondensationsreaction bei der Kalzinierung von Co1/2Ca1/2(H2PO4)2.2H2O untersucht. Die isotherme Kalzinierung des binären Dihydrogenphosphates als Ausgangsstoff wurde in einem Elektroofen bei verschiedenen Temperaturen durchgefürt. Zwischen- und Endprodukte der Reaktion wurden durch instrumentelle analytische Methoden und durch Extraktionsexperimente mit Lösungen von anorganischen Verbindungen und mit organischen Reagenzien analysiert. Es wurde weiterhin der Einfluß des Wasserdampfdruckes auf Weg, Geschwindigkeit und Ausbeute der Kondensationsreaktionen und auf die Bildung des Hauptproduktes (binäres Cyclotetraphosphat (Tetramethaphosphat)c-CoCaP4O12) untersucht.
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Trojan, M., Brandová, D., Paulik, F. et al. Mechanism of the thermal dehydration of Co1/2Ca1/2(H2PO4)2.2H2O. Journal of Thermal Analysis 36, 929–938 (1990). https://doi.org/10.1007/BF01904629
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DOI: https://doi.org/10.1007/BF01904629